Airplane



H. P. VAN KEUREN.

AIRPLANE.

APPLICATlON FILED MAY 24. 1918.

Patented July 13, 1920.

2 SHEETS-SHEET I.

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Invert for f Wiin e55 es H. P. VAN KEUREN.

AIRPLANE.

APPLICATION FILED IIIAY24, I918.

Patented July 13, 1920.

- UNITED .STATES PATENT OFFICE.

nanny P. van KEUREN, or LANSING, MIcHIeAiw.

AIRPLANE.

. improvements in airplanes of the military,

tractor type, and it consists in the combinations, constructions, and arrangements of parts herein described and claimed.

One object of my invention isfto combine in a single-seater airplane, intended primarily for use as a fighting s'cout or for use by staff observers, the following qualities in an extreme degree: agillty or maneuverability; high and low a1r speed; low landing speed; control of diving speed; high rate of climb; increased 'height' of climb for' a machine of its type; and best possiblerange of vision for the pilot.

All features of my invention are closely related and contribute directly to the attainment of the final object sought, which is to secure a military advantage overgthe enemys air forces by the employment of airplanes of su erior performance.

eferring to the drawings which are illustrative, or merely by way of example, of a preferred embodiment of my invention,

.drawn to approximate proportioiisi Figure Fig. 2. is a front'elevation 1" is a plan view; view; Fig. 3 is a side elevation; Fig. 4' is a section taken on line 1-4 of Fig. 1 ;'Fig. 5 shows a preferred means of varying the angle of incidence of the main planes, hereinreferred to later, and Fig. 6 shows a portionof the rudder and elevator control mechanism, also referred to later.

The fuselage, 9, is of rectangular section forward surmounted by a longitudinalsemigood a forward vision, along the sides of said hood, as is possible. A1; the front of the airplane, the fiat sidesand bottom of said fuselage are faired into a somewhat narrow and deep radiator, 11, and hood 10 is Suitably rounded into the radiator, 'at its top Specification of Letters Patent. P t t d Ju y 13, 20 Application filed May 24.

juncture at rudder post 16. Thus it is seen that tail sections of the fuselage, such as Fig. 4,. are triangular with base up and apex at the keel/ The purpose 'ofsuch construction of fuselage, as already described, is five-fold. 1st, it 1s desired to. use a six-cylinder, verti- 'cal, water cooled engine of the geared type which is extremely simple, light, powerful, compact, reliable, and probably best adapted to methods of American manufacture. 2nd,

it is desired to inclose such an engine in a fuselafein as small a compass as is possible, in or er to reduce fuselage sectional area ,to a minimum. 3rd, the p1lot is so situated that while protected from the blast of the airscrew, his forward view is aslarge as possible. 4th, 'the fuselage, which is of girder type. and fabric covered, is reduced in weight and its strength and rigidity increased. 5th, where the rectangular section (included by the longerons at' the cockfiit) a fairs into the triangular tail section a peculiarly advantageous warped curve is produced in the sides of the fuselage which, combined with the downward curve of the upper long'erons, produces a marked effect on the flying qualities of the airplane, in

-that the displaced air of the airscrew slipstream is not only deflected downward by the warp of the fuselage sides, but is closed in along the keel thus providin a steadying effect upgn the airplane in fiig t. Further-3,

.a considerable decrease in fuselage resistance is obtained by the form described due, to a. -i

certain amount of lift'im-p'arted to the body by the deflected air through which it passes and, also, to a propulsive force which may be likened to' that which acts on the surfboard of a bather riding upon the crest of a wave.

- In the effort to. lessen the parasite resist.- ance of the airplane of my design, I have inclosed both-the {rudder and elevator con- "trol cables 17 and 18 together with their crank arms, 19 and 20,- in the stabilizing plane 21, and tailand vertical -fin. 22, as shown in Fig. 6. Thus, rudder crank arm 19': swings inside horizontal stabilizing plane 21, and elevator crank arm 20 swings inside the vertical fin 22 and the tail of fuselage 9, each control surface being oper-.

ated inthe usual manner from the pilots rudder bar and stickthrough their respective cables 17 and 18 and suitably disposed pulleys 23.

The main plane or upper wing 24 is of tapering plan form, with ends well raked. Front and rear upper wing spars, 25 and 26,

decrease in depth outwardly from the fuselage and are joined together at the wing tips. Sections of the wing also decrease in depth progressively aschord lengths decrease. At intervals, suitable 'heavy wing ribs and diagonal internal drift wires are provided.-

by the narrow fuselage and by the narrow,

tapering, inclined lower wings 27, which inclose and streamline a combined tension and compression member 28, which takes the flying and landing load of the main plane in addition to the small flying load of said lower wing.

Ample surface, in ailerons 30, is provided for the purpose of lateral control and by the combination of the leverages of rudder, elevators, and ailerons, as shown, the most difficult evolutions may be performed with great facility and speed. Aileron control tubes 29 are inclosed within the upper wing.

Increased rate and height of climb, greater horizontal speed, slower landing speed, and control of diving speed are attained in the airplane of my invention 'as com ared to existing types of the same weig t per unit area of supporting surface and weight per 'horsepower,-by the employment of a variable angle of the main plane 24 in relation to the fuselage, 9. To this end, the main plane is hinged to a vertical supporting member connected to the fuselage at, 31 and also is hinged to the ends of members 28 of the" tapering, inclined planes 27, at points 32-32. All hinges 32- 31-32 lie on axis 33-33. By means of the vertically movable strut 34, the rear portion of the main plane is capable of being moved up or down in respect to axis 33-33,

and by said movement the angle of the main plane in respect to the horizontal axis of the fuselage, or-the thrust line, maybe varied at the will of the pilot from a slight negative angle. to approximately fifteen degrees. For the main plane, an aerofoil section is used wherein the location of the center of pressure varies but slightly as the angle of incidence increases fromnearly zero to fifteen degrees, but at the greater angle, both lift and resistance are greater.

In a climb, then, the pilot may increase the angle of his main plane as he gains altitude and may always maintain his airplane in its most favorable climbing attitude, thus increasing the rate of climb and reaching a higher altitude due to increased lift and less body drag.

In a long dive, a slower or higher speed may be attained by varying the angle of incidence, and by the same means a higher horizontal speed and safer landing speed are possible.

In Fig. 5 are shown details of the-angle of incidence control. Movable strut 34 passes through a close fitting slot 35 in member 36, and is provided at its lower end with an integral portion having a relatively quick acting, multiple, self-locking thread 37. The hub of hand wheel 38, is tapped to fit said thread 37 and is further provided with spherical bearing surfaces 39 which seat in bracket portion 40 of member 36. A turn of the hand-wheel moves strut 34 through a comparatively large vertical distance so that the entire range of angle of incidence may be utilizedquickly.

A relatively low and narrow chassis'is employed, with small wheels set well forward of the center of gravity of the airplane. This feature lessens resistance and renders possible easier landings.

The airscrew is as short as can be efliciently used for the given power and speed. This occasions a somewhat wider blade but keeps down the peripheral speed.

Other advanta es, such as ease of operation, simplicity o construction, reduced cost of manufacture, etc}, will be apparent to those skilled in the art of flying machines.

What I claim is: g 1. In-an airplane, a hinged main supporting plane operatively controlled by the pilot, a fuselage inclosing an engine at the front portion thereof,;a tractor airscrew, inclined side. planes intersecting said hinged main supporting plane. v

2. In an airplane, an airscrew at the front, a main upper supporting plane operatively hinged above a fuselage inclosing an engine forward and a cockpitin the central portion thereof, inclined lower planes extending from the fuselage and intersecting saidupper plane and hinged thereto, operatively movable control surfaces disposed in said main plane and at the rear of said fuselage, and means for taking-off and landing disposed below said fuselagei I 3. In an airplane, an airscrew at the front, a main upper operatively hinged supporting plane tapering from center to raked tips, a fuselage disposed beneath said upper plane inclosing a power mechanism with its accessory parts and a pilots cockpit, lower inclined planes disposed below said upper planes and extending from the lower part of said fuselage outwardly to meet said upper plane tapering theretoward and hinged thereto, means for controlling stalage being disposed below said wing, and inclined lower wing member's extending from said fuselage to said upper wing.

5. In an airplane, a main supporting plane above a fuselage and hinged thereto, auxiliary supporting planes extending laterally from said fuselage to intersect said main plane toward its ends, hingesat said intersection, and means for controllable Yariation of'the angle of said mainplane with said fuselage.

6. In an airplane, a fuselage connected by means of rigid members and inclined lower supporting planes to a main upper supporting plane and hinged thereto, control surfaces provided with unexposed means for said control.

HENRY P.'VAN KEUREN.

Witnesses: a R. L. CRIswELL, DAVID R. Zmmanmm. 

